sh/jshn.sh

   1 # functions for parsing and generating json
   2
   3 jshn_append() {
   4         local var="$1"
   5         local value="$2"
   6         local sep="${3:- }"
   7
   8         eval "export -- \"$var=\${$var:+\${$var}\${value:+\$sep}}\$value\""
   9 }
  10
  11 json_init() {
  12         [ -n "$JSON_UNSET" ] && eval "unset $JSON_UNSET"
  13         export -- JSON_SEQ=0 JSON_STACK= JSON_CUR="JSON_VAR" JSON_UNSET="" KEYS_JSON_VAR= TYPE_JSON_VAR=
  14 }
  15
  16 json_add_generic() {
  17         local type="$1"
  18         local var="$2"
  19         local val="$3"
  20         local cur="${4:-$JSON_CUR}"
  21
  22         [ "${cur%%[0-9]*}" = "JSON_ARRAY" ] && {
  23                 eval "local aseq=\"\${SEQ_$cur}\""
  24                 var=$(( ${aseq:-0} + 1 ))
  25                 export -- "SEQ_$cur=$var"
  26         }
  27
  28         export -- "${cur}_$var=$val"
  29         export -- "TYPE_${cur}_$var=$type"
  30         jshn_append JSON_UNSET "${cur}_$var TYPE_${cur}_$var"
  31         jshn_append "KEYS_${cur}" "$var"
  32 }
  33
  34 json_add_table() {
  35         local TYPE="$1"
  36         JSON_SEQ=$(($JSON_SEQ + 1))
  37         jshn_append JSON_STACK "$JSON_CUR"
  38         local table="JSON_$TYPE$JSON_SEQ"
  39         export -- "UP_$table=$JSON_CUR"
  40         export -- "KEYS_$table="
  41         jshn_append JSON_UNSET "KEYS_$table UP_$table"
  42         [ "$TYPE" = "ARRAY" ] && jshn_append JSON_UNSET "SEQ_$table"
  43         JSON_CUR="$table"
  44 }
  45
  46 json_add_object() {
  47         local cur="$JSON_CUR"
  48         json_add_table TABLE
  49         json_add_generic object "$1" "$JSON_CUR" "$cur"
  50 }
  51
  52 json_close_object() {
  53         local oldstack="$JSON_STACK"
  54         JSON_CUR="${JSON_STACK##* }"
  55         JSON_STACK="${JSON_STACK% *}"
  56         [[ "$oldstack" == "$JSON_STACK" ]] && JSON_STACK=
  57 }
  58
  59 json_add_array() {
  60         local cur="$JSON_CUR"
  61         json_add_table ARRAY
  62         json_add_generic array "$1" "$JSON_CUR" "$cur"
  63 }
  64
  65 json_close_array() {
  66         json_close_object
  67 }
  68
  69 json_add_string() {
  70         json_add_generic string "$1" "$2"
  71 }
  72
  73 json_add_int() {
  74         json_add_generic int "$1" "$2"
  75 }
  76
  77 json_add_boolean() {
  78         json_add_generic boolean "$1" "$2"
  79 }
  80
  81 # functions read access to json variables
  82
  83 json_load() {
  84         eval `jshn -r "$1"`
  85 }
  86
  87 json_dump() {
  88         jshn "$@" -w
  89 }
  90
  91 json_get_type() {
  92         local dest="$1"
  93         local var="$2"
  94         eval "export -- \"$dest=\${TYPE_${JSON_CUR}_$var}\""
  95 }
  96
  97 json_get_var() {
  98         local dest="$1"
  99         local var="$2"
 100         eval "export -- \"$dest=\${${JSON_CUR}_$var}\""
 101 }
 102
 103 json_select() {
 104         local target="$1"
 105         local type
 106
 107         [ -z "$1" ] && {
 108                 JSON_CUR="JSON_VAR"
 109                 return
 110         }
 111         [[ "$1" == ".." ]] && {
 112                 eval "JSON_CUR=\"\${UP_$JSON_CUR}\""
 113                 return;
 114         }
 115         json_get_type type "$target"
 116         case "$type" in
 117                 object|array)
 118                         json_get_var JSON_CUR "$target"
 119                 ;;
 120                 *)
 121                         echo "WARNING: Variable '$target' does not exist or is not an array/object"
 122                 ;;
 123         esac
 124 }